mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 00:52:01 +00:00
c7fed9d750
I copied the logic from ll/sc arch implementations, but that was wrong and makes no sense at all. Just do a straight compare-exchange instruction, just like x86. Based upon bug reports from Dennis Gilmore and Fabio Massimo. Signed-off-by: David S. Miller <davem@davemloft.net>
109 lines
2.6 KiB
C
109 lines
2.6 KiB
C
#ifndef _SPARC64_FUTEX_H
|
|
#define _SPARC64_FUTEX_H
|
|
|
|
#include <linux/futex.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/system.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
#define __futex_cas_op(insn, ret, oldval, uaddr, oparg) \
|
|
__asm__ __volatile__( \
|
|
"\n1: lduwa [%3] %%asi, %2\n" \
|
|
" " insn "\n" \
|
|
"2: casa [%3] %%asi, %2, %1\n" \
|
|
" cmp %2, %1\n" \
|
|
" bne,pn %%icc, 1b\n" \
|
|
" mov 0, %0\n" \
|
|
"3:\n" \
|
|
" .section .fixup,#alloc,#execinstr\n" \
|
|
" .align 4\n" \
|
|
"4: ba 3b\n" \
|
|
" mov %5, %0\n" \
|
|
" .previous\n" \
|
|
" .section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .word 1b, 4b\n" \
|
|
" .word 2b, 4b\n" \
|
|
" .previous\n" \
|
|
: "=&r" (ret), "=&r" (oldval), "=&r" (tem) \
|
|
: "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
|
|
: "memory")
|
|
|
|
static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
|
|
{
|
|
int op = (encoded_op >> 28) & 7;
|
|
int cmp = (encoded_op >> 24) & 15;
|
|
int oparg = (encoded_op << 8) >> 20;
|
|
int cmparg = (encoded_op << 20) >> 20;
|
|
int oldval = 0, ret, tem;
|
|
|
|
if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(int))))
|
|
return -EFAULT;
|
|
if (unlikely((((unsigned long) uaddr) & 0x3UL)))
|
|
return -EINVAL;
|
|
|
|
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
|
|
oparg = 1 << oparg;
|
|
|
|
inc_preempt_count();
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
__futex_cas_op("mov\t%4, %1", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
__futex_cas_op("add\t%2, %4, %1", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
__futex_cas_op("or\t%2, %4, %1", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
__futex_cas_op("and\t%2, %4, %1", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
__futex_cas_op("xor\t%2, %4, %1", ret, oldval, uaddr, oparg);
|
|
break;
|
|
default:
|
|
ret = -ENOSYS;
|
|
}
|
|
|
|
dec_preempt_count();
|
|
|
|
if (!ret) {
|
|
switch (cmp) {
|
|
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
|
|
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
|
|
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
|
|
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
|
|
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
|
|
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
|
|
default: ret = -ENOSYS;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static inline int
|
|
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
|
|
{
|
|
__asm__ __volatile__(
|
|
"\n1: casa [%3] %%asi, %2, %0\n"
|
|
"2:\n"
|
|
" .section .fixup,#alloc,#execinstr\n"
|
|
" .align 4\n"
|
|
"3: ba 2b\n"
|
|
" mov %4, %0\n"
|
|
" .previous\n"
|
|
" .section __ex_table,\"a\"\n"
|
|
" .align 4\n"
|
|
" .word 1b, 3b\n"
|
|
" .previous\n"
|
|
: "=r" (newval)
|
|
: "0" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT)
|
|
: "memory");
|
|
|
|
return newval;
|
|
}
|
|
|
|
#endif /* !(_SPARC64_FUTEX_H) */
|